1. Field of the Invention
The present invention relates generally to thin film magnetic transducers used to read and write data to magnetic storage media and, more particularly, to a magnetic transducer having an inverted write element with a zero delta in pole tip width.
2. Background Art
Magnetic storage media such as tape increasingly use narrow track widths in order to increase the amount of data that can be recorded. Narrow track widths require tight control of the dimension and shape of a magnetic write transducer""s top and bottom poles near and at a write gap. Narrow track widths lead to reduced recorded track pitch and tighter tolerances on write track width and the written erase bands that occur at the write track edges. As the magnetic storage media moves relative to a magnetic write transducer, it is generally the trailing pole of the magnetic write transducer (i.e., the top pole or the bottom pole dependent on the direction of motion of the magnetic storage media) that determines the effective size of the track width written on the magnetic storage media.
Accordingly, what is needed is a magnetic transducer which provides improved control over the write track width and the written erase bands. It would be desirable if such a magnetic transducer provided the same write track width in both directions of movement of the magnetic storage media relative to the magnetic transducer while providing relatively small erase bands. In such case, the magnetic transducer would provide the same track width regardless of whether the top pole or bottom pole is the trailing pole while providing relatively small erase bands.
It is an object of the present invention to provide a magnetic transducer having an inverted write element with a zero delta in pole tip width.
It is another object of the present invention to provide a magnetic transducer having an inverted write element with a zero delta in pole tip width which provides improved control over the write track width and the written erase bands.
It is a further object of the present invention to provide a magnetic transducer having an inverted write element with a zero delta in pole tip width which provides the same write track width in both directions of movement of magnetic storage media relative to the magnetic transducer while providing relatively small erase bands.
It is still another object of the present invention to provide a magnetic transducer having an inverted write element including a top pole and a bottom pole configured to provide the same write track width and relatively small erase bands when either the top pole or bottom pole is the trailing pole.
It is still a further object of the present invention to provide a method of fabricating a magnetic transducer in accordance with the objects set forth above.
In carrying out the above objects and other objects, the present invention provides a magnetic transducer including a bottom pole and a top pole. The bottom pole has an upper portion and a lower portion. The bottom pole upper portion has an upper portion width and the bottom pole lower portion has a lower portion width. The bottom pole upper portion width is less than the bottom pole lower portion width. The top pole has a main portion formed opposite to the bottom pole upper portion. The top pole main portion has a main portion width. The top pole main portion width is substantially equal to the bottom pole upper portion width. A write gap layer is interposed between the top pole main portion and the bottom pole upper portion.
Further, in carrying out the above objects and other objects, the present invention provides a method of fabricating a magnetic transducer. The method includes forming a bottom pole having an upper portion and a lower portion. The bottom pole upper portion has an upper portion width and the bottom pole lower portion has a lower portion width. The bottom pole upper portion width is less than the bottom pole lower portion width. The method further includes forming a top pole having a main portion opposite to the bottom pole upper portion. The top pole main portion has a main portion width which is substantially equal to the bottom pole upper portion width.
Prior to the step of forming a top pole, the method may further include depositing a write gap, layer on the bottom pole and then forming the top pole such that the write gap layer is interposed between the top pole main portion and the bottom pole upper portion.
Forming the top pole may include forming a top pole side portion on each side of the top pole main portion offset from the top pole main portion in a direction away from the bottom pole. Prior to the step of forming a top pole, the method may include forming an electrical insulating layer on each side of the bottom pole upper portion at a level above the bottom pole upper portion and then forming the top pole side portions over the electrical insulating layer. The electrical insulating layer may include alumina. The method may include depositing a write gap layer on the electrical insulating layer and the bottom pole upper portion and then forming the top pole such that the write gap layer is interposed between the top pole main portion and the bottom pole upper portion and is interposed between the top pole side portions and the electrical insulating layer.
Still further, in carrying out the above objects and other objects, the present invention provides a magnetic transducer including a bottom pole, an electrical insulating layer, and a top pole. The bottom pole has an upper portion and a lower portion. The bottom pole upper portion has an upper portion width and the bottom pole lower portion has a lower portion width. The bottom pole upper portion width is less than the bottom pole lower portion width. The electrical insulating layer is on each side of the bottom pole upper portion width at a level above the bottom pole upper portion. The top pole has a main portion opposite to the bottom pole upper portion. The top pole main portion has a main portion width which is substantially equal to the bottom pole upper portion width. The top pole further has a side portion on each side of the top pole main portion width. The top pole side portions are formed opposite to the electrical insulating layer such that the top pole side portions are offset from the top pole main portion in a direction away from the level above the bottom pole upper portion. A write gap layer may be interposed between the top pole main portion and the bottom pole upper portion and may be interposed between the top pole side portions and the electrical insulating layer.
The bottom pole upper portion width defines a first write track width when the bottom pole is a trailing pole and the top pole main portion width defines a second write track width when the top pole is the trailing pole. The first and second write track widths are substantially equal as the bottom pole upper portion width and the top pole main portion width are substantially equal.
A magnetic write fringing field extends between the bottom pole upper portion and the top pole main portion when a magnetic writing signal is induced. The write fringing field extending non-perpendicularly between the bottom pole upper portion and the top pole are minimized as a result of the top pole side portions being formed offset from the top pole main portion in a direction away from the level above the bottom pole upper portion.
The advantages associated with the present invention are numerous. For example, the inverted write element with a zero delta in pole tip width provides improved bi-directional write track width control while providing an opportunity for improved control of the written erase bands. Thus, the write track width in both directions of magnetic storage media movement are roughly the same while the written erase bands are relatively small. These features improve the track mis-registration budget thereby permitting higher track densities.
The above objects and other objects, features, and advantages of the present invention are readily apparent from the following detailed description when taken in connection with the accompanying drawings.